1. Field of the Invention
The present invention is directed, generally, to an antenna for radio-operated communication terminal equipment and, more specifically, to a planar inverted-F antenna for covering a number of different frequency bands.
2. Description of the Prior Art.
Particularly in view of developments in mobile radio telephone technology, antennas are required to simultaneously cover a number of frequency bands. Moreover, the marketplace is demanding both smaller and cheaper mobile ratio telephone devices. Antennas are therefore required that have a low space requirement, that can be unproblemmatically designed to function in either a plurality of frequency bands or a broadband frequency range and that can be inexpensively manufactured.
Solutions are known in this field wherein two or more individual planar inverted-F antennas are integrated in a piece of communication terminal equipment. However, one or more feed points are then required which need to be driven via suitable circuitry; thus, representing an additional outlay.
An object of the present invention, therefore, is to specify an antenna for radio-operated communication terminal equipment that is configured as a planar inverted-F antenna which, however, is also in the position of simultaneously covering a plurality of frequency bands.
An antenna for radio-operated communication terminal equipment for achieving the above-mentioned object is characterized by a planar inverted-F antenna having a feed point and one or more ground connections that is designed for a predetermined, lower emission frequency that has its size defining the overall dimension of the antenna. Such antenna further includes one or more notchings or graduations in longitudinal direction with which one or more geometrical paths derive that are composed of a plurality of straight-line or curved individual paths, and that proceed from the feed point or some other corner or end point to one of the corner points created by the notchings or graduations. Moreover, over the course of such paths an emittable wave is formed with a higher frequency than the predetermined, lower frequency.
The inventive antenna is easy and inexpensive to manufacture, has a small space requirement and can be unproblemmatically designed to function in either a plurality of frequency bands or a broadband frequency range.
Additional features and advantages of the present invention are described in, and will be apparent from, the Detailed Description of the Preferred Embodiments and the Drawings.